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| author | Rik van Riel <riel@redhat.com> | 2013-10-07 14:29:39 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-10-09 16:48:21 +0400 |
| commit | de1c9ce6f07fec0381a39a9d0b379ea35aa1167f (patch) | |
| tree | d96bf1a2b25dfa84d3fe5f6fe00fb780800e3ef3 /kernel/sysctl.c | |
| parent | 1e3646ffc64b232cb14a5ef01d7b98997c1b73f9 (diff) | |
| download | linux-de1c9ce6f07fec0381a39a9d0b379ea35aa1167f.tar.xz | |
sched/numa: Skip some page migrations after a shared fault
Shared faults can lead to lots of unnecessary page migrations,
slowing down the system, and causing private faults to hit the
per-pgdat migration ratelimit.
This patch adds sysctl numa_balancing_migrate_deferred, which specifies
how many shared page migrations to skip unconditionally, after each page
migration that is skipped because it is a shared fault.
This reduces the number of page migrations back and forth in
shared fault situations. It also gives a strong preference to
the tasks that are already running where most of the memory is,
and to moving the other tasks to near the memory.
Testing this with a much higher scan rate than the default
still seems to result in fewer page migrations than before.
Memory seems to be somewhat better consolidated than previously,
with multi-instance specjbb runs on a 4 node system.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-62-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sysctl.c')
| -rw-r--r-- | kernel/sysctl.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index e509b90a8002..a159e1fd2013 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -391,6 +391,13 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, + { + .procname = "numa_balancing_migrate_deferred", + .data = &sysctl_numa_balancing_migrate_deferred, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, #endif /* CONFIG_NUMA_BALANCING */ #endif /* CONFIG_SCHED_DEBUG */ { |